Improvement in clamps for grinding watch-crystals



A. G. NORTON.

Clamp for Grinding Watch-Crystals. No.163,683. Patented May 25,1875.

THEGRAPHIG CD.PHOTO-LITH.39B=4I PARK PLAGEJLY.

UNITED STATES PATENT OFFICE.

ARTHUR O. NORTON, OF MONONA, IOWA.

IMPROVEMENT IN CLAMPS FOR GRINDING WATCH-CRYSTALS.

Specfication forming part of Letters Patent No. 163,683., dated May 25, 1875; application filed March 29, 1875.

To all whom it may concern:

Be it known that I, ARTHUR O. NORTON, of Monona, in the county of Clayton and State of Iowa, have invented a new and Improved Orystal-Grinder, of which the follow ing is a specification:

My invention consists of a pair of rubberfaced clamping-disks, arranged in apair of jointed clamping-jaws, having a clampingscrew for fastcnin g them to receive and hold between them a watch-crystal, and revolve with it, when the edge of a crystal is presented to the face of a grindstone, so that the crystal will be ground on the edge suitably for fitting in the rim of a watch-case.

Figure 1 is a perspective view of my improved crystal-grinder, with a crystal between the clamps and presented against the face of a grindstone, and Fig. 2 is a side elevation of the grinder.

Similar letters of reference indicate corresponding parts.

A and B represent the clamping-disks, with elastic faces, and arranged on independent axles O in the arms D E of the clamp, so as to receive the crystal F between them, as shown. G is the clamp-screw, and H the joint of the arms of the clamp. The crystal is secured between the clamping-disks, and the edge is then presented to the face of the grindstone L, at such an angle asto give the proper bevel to the edge J of the crystal, and to turn it and cause it to be ground alike all around the edge.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The revolving elastic-faced disks A and B on independent axles O, in combination with jointed clamping-arms D E and a clampscrew, G, substantially as specified.

ARTHUR O. NORTON. Witnesses:

PAUL EGBERT, IRA P. WINTER. 

